Overview
The common cold is a mild viral infection of the upper respiratory tract, mainly affecting the nose and throat. Over 200 different viruses can cause it, with rhinoviruses being the most common. Colds are self-limiting and usually resolve within 7 to 10 days.
How common is it?
Colds are very common. CDC estimates that adults in the United States have two to three colds a year on average, while children often have more. Frequency varies between people and settings.
Causes and risk factors
Viruses spread from person to person through respiratory droplets from coughs and sneezes, and through contact with contaminated surfaces followed by touching the nose or eyes.
Common risk factors
- Close contact with an infected person
- Touching contaminated surfaces then touching face
- Cold weather (people spend more time indoors in close contact)
- Weakened immune system
- Lack of sleep and high stress
- Children (more colds, more virus shedding)
Symptoms
- Runny or blocked nose
- Sneezing
- Sore throat
- Mild cough
- Mild headache
- Low-grade fever (more common in children)
- Feeling generally unwell
- Symptoms peak around day 2 to 3, improving by day 7
When to see a doctor
Get medical advice if symptoms worsen, fever lasts more than 3 days or symptoms have not improved after 10 days. Seek earlier advice if you have diabetes, heart or lung disease or a weakened immune system. Chest pain or breathing difficulty needs urgent assessment; severe breathing difficulty, collapse or confusion needs emergency help. Flu and COVID-19 can resemble a cold; higher-risk people may need early testing and treatment.
Diagnosis
Clinical diagnosis based on symptoms. Testing is not needed for routine colds. Consider testing for flu or COVID-19 if symptoms are more severe.
Treatments
Symptomatic relief
Paracetamol or ibuprofen can ease discomfort if suitable; check medicine labels to avoid duplicate ingredients. Saline nasal spray may help congestion. Warm honey and lemon may soothe a cough, but never give honey to a baby under 1 year. Ask a pharmacist about child-safe products and about painkillers if pregnant or if you have kidney disease.
Rest and fluids
Adequate rest supports immune function. Staying hydrated thins mucus and prevents dehydration.
Decongestant nasal sprays
Decongestant nasal sprays or drops may relieve a blocked nose briefly. Follow the product leaflet and do not use for more than 5 days because congestion can rebound. Check with a pharmacist first if you have diabetes, high blood pressure, heart disease or take other medicines. Do not use decongestants during pregnancy.
Self-care and lifestyle
- Wash hands frequently, especially after blowing nose or coughing
- Avoid touching your eyes, nose, or mouth
- Dispose of tissues immediately and wash hands after
- Rest at home to recover faster and avoid spreading the virus
Prevention
Regular handwashing is the single most effective way to prevent cold spread. There is no vaccine for the common cold due to the huge variety of viruses involved.
Sources for targeted updates
Updated: 24 October 2026. Targeted corrections to frequency, treatment, urgent-care guidance. This update covers the named sections; a full review of the remaining guide is pending.